Structure and haptic presentation device

Abstract

A structure according to an embodiment of the present technology includes a casing, a pressure generator, and an acoustic metamaterial. The casing includes at least one or more openings. The pressure generator is disposed in the casing and generates an air pressure toward the opening. The acoustic metamaterial is fitted into the opening and includes a first through-hole formed such that the air pressure passes through the first through-hole linearly, and a second through-hole formed such that the air pressure passes through the second through-hole spirally, the acoustic metamaterial being formed such that a ratio of a sum of a cross-sectional area of the first through-hole and a cross-sectional area of the second through-hole to a cross-sectional area of the pressure generator is smaller than 0.94.

What is claimed is: 
     
         1 . A structure, comprising:
 a casing including at least one or more openings;   a pressure generator that is disposed in the casing and generates an air pressure toward the opening; and   an acoustic metamaterial that is fitted into the opening and includes
 a first through-hole formed such that the air pressure passes through the first through-hole linearly, and 
 a second through-hole formed such that the air pressure passes through the second through-hole spirally, the acoustic metamaterial being formed such that a ratio of a sum of a cross-sectional area of the first through-hole and a cross-sectional area of the second through-hole to a cross-sectional area of the pressure generator is smaller than 0.94. 
   
     
     
         2 . The structure according to  claim 1 , wherein
 the opening is provided in a direction coaxial with a direction in which the air pressure is compressed by the pressure generator.   
     
     
         3 . The structure according to  claim 1 , wherein
 the opening is provided in an axial direction different from a direction in which the air pressure is compressed by the pressure generator.   
     
     
         4 . The structure according to  claim 1 , wherein
 a sound-absorbing material is disposed in the casing, and   the sound-absorbing material is formed of a laminate of fibers or a porous material.   
     
     
         5 . The structure according to  claim 1 , wherein
 the pressure generator includes a voice coil motor or a fan.   
     
     
         6 . The structure according to  claim 1 , wherein
 the casing includes two or more of the openings, and   the acoustic metamaterial is fitted into each of the openings.   
     
     
         7 . The structure according to  claim 6 , wherein
 the two or more of the openings are opened in an identical direction, and   the casing includes a divider provided between the openings.   
     
     
         8 . The structure according to  claim 1 , wherein
 the second through-hole has two or more types of angles.   
     
     
         9 . The structure according to  claim 8 , wherein
 the second through-hole is formed to have the two or more types of angles in a vicinity of an outlet from which the air pressure is exhausted.   
     
     
         10 . The structure according to  claim 1 , wherein
 the acoustic metamaterial includes a magnetic circuit, and   at least one or more of a cross-sectional area of a passage connecting an inlet and an outlet of the second through-hole, a length of the acoustic metamaterial in a direction coaxial with a direction in which the air pressure passes through the first through-hole, or an angle formed by the passage dynamically change by driving of the magnetic circuit.   
     
     
         11 . The structure according to  claim 1 , wherein
 the first through-hole is a columnar shape, and   the second through-hole includes a plurality of inlets and outlets.   
     
     
         12 . A haptic presentation device, comprising:
 a casing including at least one or more openings opened toward a user;   a pressure generator that is disposed in the casing and generates an air pressure toward the opening; and   an acoustic metamaterial that is fitted into the opening and includes
 a first through-hole formed such that the air pressure passes through the first through-hole linearly, and 
 a second through-hole formed such that the air pressure passes through the second through-hole spirally, the acoustic metamaterial being formed such that a ratio of a sum of a cross-sectional area of the first through-hole and a cross-sectional area of the second through-hole to a cross-sectional area of the pressure generator is smaller than 0.94.